1. Field of the Invention
This invention relates to a media data coding and multiplexing apparatus, a media data coding and multiplexing system, and a media data coding and multiplexing method for coding, packeting, and multiplexing a plurality of pieces of media data.
2. Description of the Related Art
In recent years, development of a highly efficient coding apparatus of a video signal has been shifting to development of a system intended for high-definition video including HDTV signals. To handle high-definition video, inevitably high-speed processing is required and generally is accomplished by parallel processing.
FIG. 5 is a block diagram of a media data coding and multiplexing apparatus in a related art. In the figure, numeral 50 denotes a video signal, numeral 60 denotes an audio signal, numeral 70 denotes a data signal, numeral 51 denotes a video coding section, numeral 61 denotes an audio coding section, numeral 71 denotes a multiplexing section, numeral 55 denotes a coded video signal, numeral 65 denotes a coded audio signal, and numeral 75 denotes a packet string.
FIG. 6 is a block diagram to show the configuration of a video coding section in the related art shown inJP-A-7-115649. In the figure, numeral 56 denotes a video signal dividing circuit, numeral 57 denotes a transmission circuit, numeral 58 denotes a quantization control circuit, numerals 511, 521, 531, and 541 denote divided video signals numerals, 512, 522, 532, and 542 denote coding units, numerals 513, 523, 533, and 543 denote coded video signals, numerals 514, 524, 534, and 544 denote transmission buffers, 515, 525, 535, and 545 denote packeted video signals, numerals 516, 526, 536, and 546 denote transmission buffer control signals, numeral 517, 527, 537, and 547 denote transmission buffer information pieces, numerals 518, 528, 538, and 548 denote quantization control signals, and numerals 519, 529, 539, and 549 denote video information pieces.
Next, the operation of the media data coding and multiplexing apparatus in the related art will be discussed with reference to FIG. 5.
The video signal 50 is coded in the video coding section 51 and is output to the multiplexing section 71 as the coded video signal 55. Likewise, the audio signal 60 is coded in the audio coding section 61 and is output to the multiplexing section 71 as the coded audio signal 65. The multiplexing section 71 packets and multiplexes the data signal 70 and the input coded video signal 55 and coded audio signal 65 and outputs the signals as the packet string 75.
Further, the operation of the video coding section in the related art will be discussed with reference to FIG. 6.
The video signal 50 input to the video coding section 51 is divided into four signals in the video signal dividing circuit 56 and the divided video signals 511, 521, 531, and 541 are output to the coding units 512, 522, 532, and 542 respectively.
The quantization control circuit 58 receives the video information pieces 519, 529, 539, and 549 each representing the nature of the video images processed in the coding units 512, 522, 532, and 542 and also receives the transmission buffer information pieces 517, 527, 537, and 547 each representing the state of the corresponding transmission buffer, generates the quantization control signals 518, 528, 538, and 548 used in the coding units 512, 522, 532, and 542 respectively, and outputs the quantization control signals 518, 528, 538, and 548 to the coding units 512, 522, 532, and 542 respectively.
The divided video signals 511, 521, 531, and 541 are coded in the coding units 512, 522, 532, and 542 based on the quantization control signals 518, 528, 538, and 548 and the coded video signals 513, 523, 533, and 543 are output to the transmission buffers 514, 524, 534, and 544 respectively.
The coded video signals 513, 523, 533, and 543 are buffered in the transmission buffers 514, 524, 534, and 544 respectively and the buffered video signals 515, 525, 535, and 545 are output to the transmission circuit 57 in order based on the transmission buffer control signals 516, 526, 536, and 546 output from the transmission circuit 57.
The buffered video signals 515, 525, 535, and 545 are output from the transmission circuit 57 as the coded video signal 55 of the video signal 50.
In the media data coding and multiplexing apparatus in the related art, as shown in FIG. 6, to handle low-definition video, one module consisting of the coding unit and the transmission buffer is provided and to handle high-definition video, two or more modules, for example, the coding units 512, 522, 532, and 542 and the transmission buffers 514, 524, 534, and 544 are provided for performing parallel processing, thereby realizing easiness of hardware configuration. In this case, however, easiness of hardware configuration containing the multiplexing function with any other media data such as audio data is not considered and the coding section for coding any other media data such as audio data and the multiplexing section for multiplexing a plurality of pieces of media data such as audio data are configured as the audio coding section 61 and the multiplexing section 71 aside from the video coding section 51, as shown in FIG. 5. Thus, the output function of multiplexed coded data cannot be provided simply by combining a plurality of modules and parallel processing control circuits of the video signal dividing circuit 56, etc.